Is anyone using a variac?

JCH

JCH

El Nacho
The UPS guy delivered mine yesterday. So far I've only tried it out with my old Silvertone 1482. I like it! The amp really responds to different voltage settings. At 95v it sounds like a totally different amp.

I bought it primarily as a piece of test gear, but couldn't wait to plug an amp into it for some brown sound. I have a couple questions for those with experience:

What voltage is working best for you?

I've heard different opinions.. Do you beleive this to be harmful to an amplifier?

I would be glad to hear any tips, or tricks that would help when using one.

TIA.... John
 
Hi JCH,

I have a Line 6 Pod XT Live and in the manual they modeled the Variac Marshall. They said something to the effect that the rumored sound was "not too far from wrong"...or something similar. I got the impression that they didn't think it worked. Beyond that,even if you did manage to match EVH sound using a variac, I read an article years ago that said when he's on tour, he has his amp tubes changed every night. Try it out and see what happens,but to me, the amp was designed to operate at a certain voltage, to put a lot less or alot more voltage in it, is probably not good for any of the circuitry.JMO...


J.P.
 
JCH said:
The UPS guy delivered mine yesterday. So far I've only tried it out with my old Silvertone 1482. I like it! The amp really responds to different voltage settings. At 95v it sounds like a totally different amp.

I bought it primarily as a piece of test gear, but couldn't wait to plug an amp into it for some brown sound. I have a couple questions for those with experience:

What voltage is working best for you?

I've heard different opinions.. Do you beleive this to be harmful to an amplifier?

I would be glad to hear any tips, or tricks that would help when using one.

TIA.... John
Click to expand...


YES, it is harmful for you amp. It will distroy your tubes, and isn't very good for your tranies either. The problem is that it cuts the voltage on the heaters, which means that your tubes are operating too cool. This causes cathode striping, and will ruin your tubes in short order. EVH has to change tubes on a nightly basis because of this shit. If you want that sound, you can get your amp modified so that you have a lower voltage going to everything buy the heaters, but it is going to require custom made transformers, and so it will be fucking EXPENSIVE, but then, so is buying new tubes every night.

Come to think of it, most Silvertones are transformerless designs. Those things are dangerous enough WITHOUT fucking around with their voltage. I'm not sure, but I've got a bad feeling that you could be taking your life in your hands by doing that shit.



Light

"Cowards can never be moral."
M.K. Gandhi
 
JCH said:
The UPS guy delivered mine yesterday. So far I've only tried it out with my old Silvertone 1482. I like it! The amp really responds to different voltage settings. At 95v it sounds like a totally different amp.

I bought it primarily as a piece of test gear, but couldn't wait to plug an amp into it for some brown sound. I have a couple questions for those with experience:

What voltage is working best for you?

I've heard different opinions.. Do you beleive this to be harmful to an amplifier?

I would be glad to hear any tips, or tricks that would help when using one.

TIA.... John
Click to expand...



i'm confused, do you wanna know about variax' or silvertones???

:confused: :confused: :confused: :confused: :confused:

:rolleyes:
 
faderbug said:
i'm confused, do you wanna know about variax' or silvertones???

:confused: :confused: :confused: :confused: :confused:

:rolleyes:
Click to expand...



Neither, he's asking about a variac, which is a variable transformer used to change the voltage coming out of the wall. Eddie Van Halen used one on his Marshal Plexi to get his "brown sound." If there is any secret to his sound (other than his hands), it is the variac.


Light

"Cowards can never be moral."
M.K. Gandhi
 
Light said:
YES, it is harmful for you amp. It will distroy your tubes, and isn't very good for your tranies either. The problem is that it cuts the voltage on the heaters, which means that your tubes are operating too cool. This causes cathode striping, and will ruin your tubes in short order. EVH has to change tubes on a nightly basis because of this shit. If you want that sound, you can get your amp modified so that you have a lower voltage going to everything buy the heaters, but it is going to require custom made transformers, and so it will be fucking EXPENSIVE, but then, so is buying new tubes every night.

Come to think of it, most Silvertones are transformerless designs. Those things are dangerous enough WITHOUT fucking around with their voltage. I'm not sure, but I've got a bad feeling that you could be taking your life in your hands by doing that shit.
Click to expand...

LOL... I don't think my life's in too much danger... Thanks for the reply. It's obviously something you feel strongly about.

This is from an article I read...."The jury is out on whether using a variac in this way will damage your amp. The general consensus is that it will wear out your tubes more quickly and perhaps wear internal components faster. Some amps, however, are designed with a High/Low Power switch, which is a type of variac switch built in to the amp. These do not damage the amp at all, and unlike hardware variacs, they can often cut the power rating in half. For a low-wattage amp putting out less than 10W RMS, a variac power switch could bring the amp down to less than 5W, which is almost microwattage amp territory. Variacs generally cost $200 or more." This is typical of the articles I read.
I value the feedback from this forum... Any other opinions?


... dude don't bag on my ol' Silvertone It's a great little amp. I swapped out the original speaker with a Jensen . That really brought it to life. I've got a few other vintage tube amps. The silvertone is the smallest of the bunch....
 
JCH said:
LOL... I don't think my life's in too much danger... Thanks for the reply. It's obviously something you feel strongly about.

This is from an article I read...."The jury is out on whether using a variac in this way will damage your amp. The general consensus is that it will wear out your tubes more quickly and perhaps wear internal components faster. Some amps, however, are designed with a High/Low Power switch, which is a type of variac switch built in to the amp. These do not damage the amp at all, and unlike hardware variacs, they can often cut the power rating in half. For a low-wattage amp putting out less than 10W RMS, a variac power switch could bring the amp down to less than 5W, which is almost microwattage amp territory. Variacs generally cost $200 or more." This is typical of the articles I read.
I value the feedback from this forum... Any other opinions?


... dude don't bag on my ol' Silvertone It's a great little amp. I swapped out the original speaker with a Jensen . That really brought it to life. I've got a few other vintage tube amps. The silvertone is the smallest of the bunch....
Click to expand...


Well, that "article" is by someone who clearly has no clue what they are talking about. There is absolutly NO similarity between a "hi/low power switch" (which typically switches two of the output tubes out of the circuit) and a variac (which cuts the input voltage). There is simply no question that droping the input voltage will fry the shit out of your tubes, and FAST.

And I'm not saying the Silvertone doesn't sound very good, but many of them have a VERY unsafe design. Most of them don't use any power or output transformers, instead running the heaters on the tubes in series instead of parallel, which works fine until one of your tubes blow out, and then you are running your tubes without heaters. Now, it is pretty clear you don't know much about tubes, so I'll just say that there aren't many ways to fry a tube faster than running it without it's heater (unless maybe you want to over-bias it to get it red plating).

Now, I just looked up the schematic for your amp, and it DOES have transformers, but that just means you are putting some expensive an difficult to find parts at risk by using a variac. Particularly when you consider the difficulty of locating decent tubes these days (when it comes to preamp tubes, you can't), It just seems like a bad idea to me.



Light

"Cowards can never be moral."
M.K. Gandhi
 
Light said:
Neither, he's asking about a variac, which is a variable transformer used to change the voltage coming out of the wall. Eddie Van Halen used one on his Marshal Plexi to get his "brown sound." If there is any secret to his sound (other than his hands), it is the variac.


Light

"Cowards can never be moral."
M.K. Gandhi
Click to expand...


cheers, i thought jch had misspelled variax and i tend to read too fast.

at least now i know what a variac is and no i'm not using one.

:D
 
The transformers are the black thingys aren't they :rolleyes: f'kn duh! You think you could give someone the benefit of the doubt before you start flaming them? I might have a little more on the ball then you think.
 
If you want to lower the plate voltage while keeping the heater voltage at spec, changing a few choice resistors will do generally do the trick. It wouldn't be too tough to integrate that mod into a switch.
 
Light said:
YES, it is harmful for you amp. It will distroy your tubes, and isn't very good for your tranies either. The problem is that it cuts the voltage on the heaters, which means that your tubes are operating too cool. This causes cathode striping, and will ruin your tubes in short order. EVH has to change tubes on a nightly basis because of this shit. If you want that sound, you can get your amp modified so that you have a lower voltage going to everything buy the heaters, but it is going to require custom made transformers, and so it will be fucking EXPENSIVE, but then, so is buying new tubes every night.

Come to think of it, most Silvertones are transformerless designs. Those things are dangerous enough WITHOUT fucking around with their voltage. I'm not sure, but I've got a bad feeling that you could be taking your life in your hands by doing that shit.



Light

"Cowards can never be moral."
M.K. Gandhi
Click to expand...

It seems to me that it would be a pretty simple project to build a separate power supply for the heater circuit that wouldn't run off the Variac. Heck, you could probably strip what you'd need out of any old junked tube amp. It would be a simple mod to cut the heater circuit loose from the power supply and wire it to a jack on the chassis for access by the external supply. It sure would be cheaper than replacing tubes every night.
 
It seems to me that it would be a pretty simple project to build a separate power supply for the heater circuit that wouldn't run off the Variac. Heck, you could probably strip what you'd need out of any old junked tube amp. It would be a simple mod to cut the heater circuit loose from the power supply and wire it to a jack on the chassis for access by the external supply. It sure would be cheaper than replacing tubes every night.
Click to expand...
I am guessing you "Could", but then it wouldn't sound like the amp running off the Variac, now would it? So it would be self defeating.

You should try it though, I'd like to hear your results. Maybe you're on to something there....
 
turnitdown said:
I am guessing you "Could", but then it wouldn't sound like the amp running off the Variac, now would it? So it would be self defeating.

You should try it though, I'd like to hear your results. Maybe you're on to something there....
Click to expand...


Why would it sound any different? I don't think that the tube heater voltage contributes to the "brown sound"; it's all about the bias voltages, innit?
 
Save the Variac for situations where your mains (powers supply) from source is too hot. I lived in West Texas for years and our local supplier ran the lines at 135 v. !!! can you beleive it? I was told by a local electrician fwiw that they did so beacause of transmission loss b/c of the extremely dry air (low humidity). We used variacs to regulate the studio power supply. Granted we are talking MASSIVE VARIAC. None the less. Use variac at your own risk. Light is correct about the heaters. I think your garden variety 6l6 or El 34 requires a 6.3 v. supply ( could be wrong) but nonetheless operating a tube with a cold heater = not good. If it sounds good and you are willing to risk damage that is entirely up to you.
 
I don't think that the tube heater voltage contributes to the "brown sound";
Click to expand...
I thought it was... (maybe I'm wrong).... Otherwise people could just reduce the bias voltage, and get the benefit w/o the damage.

Like I said though.... maybe I am wrong.
 
turnitdown said:
I thought it was... (maybe I'm wrong).... Otherwise people could just reduce the bias voltage, and get the benefit w/o the damage.

Like I said though.... maybe I am wrong.
Click to expand...



No, the heater voltage is not going to have any effect on the sound. It is, after all, not in any way involved with the signal path. It is just there to keep the tubes warm.

And yeah, most tubes (except for some diode which are used as rectifier tubes) run at 6.3v.


Light

"Cowards can never be moral."
M.K. Gandhi
 
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